As is well known, in the railroad industry, coupling devices have been used extensively for a great many years to connect the adjacent ends of a pair of railway cars together to form a train consist of several individual cars. It is equally well known that on those railway cars which will be used in interchange service, the coupling devices used must receive approval by the Association of American Railroads before they can be installed for service on such railway cars. In this railroad application, it has come to be quite well known that these coupling devices generally perform a number of functions which are of importance. Obviously, one of the important functions performed by the standard railway coupling device is that it facilitates both the connection and the disconnection of individual railway cars to and from, respectively, a train consist. Another function of importance, with respect to such standard railway coupling device, is that it will enable such railway cars to successfully negotiate the various curved portions of the track structure which are normally encountered during operation of the train consist. Additionally, these coupling devices are designed to permit a number of individual railway cars to be readily and easily combined so that a train consist can be formed. Further, these coupling devices enable such railway cars to be easily separated into individual cars again for the purpose of either loading or unloading cargo thereto or therefrom, respectively, as required. This feature permits a railroad to leave a particular railroad car at a customer's plant while they are either delivering or picking up other cars located at other locations. The problem of extraneous foreign material, solved by the present invention, is not present in this standard coupling device because the mating connecting components are all disposed in a substantially vertical direction and, therefore, would not retain such foreign material.
In the more recent past, however, the railroad industry has come to recognize that there are a number of rather significant advantages which can be achieved by the interconnection of several railway cars together in a manner which will form a generally semi-permanent unit. This is particularly the case, for example, where such individual railway cars are adapted for use in what has come to be commonly known in the railway industry as "piggyback" or intermodal service. One of the primary reasons for this is that the cargo to be either loaded or unloaded is brought to or removed from, respectively, a central location. In general, these central cargo handling locations are owned and operated by the railroad handling the cargo. This cargo, generally, is over-the-road trailers or rather large containers such as containers used to ship cargo by ocean going vessels. The individual railway cars which have been connected together in such substantially semi-permanent fashion are commonly known in the railroad industry as either a "5-pack" or "10-pack".
Regardless of whether a 5-pack or a 10-pack unit is being used, it will not require the use of these standard couplers, except at the outer end of each unit. One of the primary reasons why such standard coupling devices are not required, in this application, is that in view of their dedicated-type service, these 5-pack or 10-pack units will normally only be broken on a periodic basis. Generally, for example, the breaking of these units will only take place when maintenance must be carried out on an individual coupler component or on some other critical component positioned on such railway cars which requires such railway cars to be taken out of service at least temporarily. The coupling device used intermediate the outer ends of the cars making up these 5-pack and/or 10-pack units are most commonly known in the railroad industry as articulated couplers. It is such articulated couplers where the problem solved by the present invention exists as will become clear as the description proceeds.
Nevertheless, it has become evident to the railroad industry that with the use of this articulated coupling arrangement, it is possible for them to achieve a significant reduction in their operating and equipment costs. This cost reduction can be attributed to a variety of reasons. These reasons include, for example, lower equipment weight which results in enhanced energy savings. In addition, fewer railway car trucks are required with the articulated coupling arrangement which results in both lower equipment cost as well as a significant reduction in maintenance requirements. Further, draft gear is only required behind the standard coupling device located on the extreme outer ends of such 5-pack and 10-pack unit. Such reduction in the number of draft gears required, like the reduction in the number of railway car trucks, result in lower equipment and lower maintenance costs.
At the present time, however, with the relatively extensive use of such substantially semi-permanent coupling arrangements, the railroad industry, in conjunction with the railway equipment supplier, has determined that it is of critical importance for a close-buttoned relationship to be maintained between the coupler draft components which are normally present in a particular articulated-type coupling arrangement. Further, contributing to such importance of this close-buttoned relationship requirement is the ever increasing loads which must be carried by the modern railway cars and train consists. Such heavier loads being necessary so that such railway industry can remain competitive with other forms of cargo distribution. This close-buttoned relationship has been found necessary, for example, so that the detrimental effects of the impact forces which are normally encountered during in-track operation of the train consist can be reduced and maintained at an acceptable level. In this manner, the possible damage that could be incurred not only to the cargo, but also to the railway equipment can be held to an absolute minimum. Such impact forces will normally be encountered during the normal buff operation of such train consist.
With the above discussion in mind, attention is now directed to a particular well known prior art type articulated coupling arrangement which is used for the purpose of connecting adjacent ends of a pair of railway cars together in such semi-permanent fashion. This prior art articulated coupling arrangement is taught in U.S. Pat. No. 4,258,628. As has been generally illustrated therein, this particular articulated coupling arrangement includes a male connection member and a female connection member. In this coupling arrangement, the male connection member is secured to one end of a first railway car body member and the female connection member is secured to one end of a second railway car body member, such that the male connection member is horizontally insertable into a cavity within the female connection member and such male and female connection members are joined together with clearance sufficient to permit pivotal movement of one component with respect to the other and,
The female connection member, in this articulated coupling arrangement, is positioned for rotation within a center plate bowl portion located on the upper surface of a bolster member positioned intermediate a pair of side frame members of a railway car truck member. Such rotatable-type connection of such female connection member in the center plate bowl portion is accomplished in a manner that is generally well recognized in the railway art and for that reason will not be discussed in any further detail. The outer end portion of the male connection member is disposed for relative movement within a cavity located at the outer end portion of the female connection member. A pin member, positioned in a vertical plane, is utilized in this prior art articulated coupling arrangement to connect such outer end portion of the male connection member within such cavity at such outer end of the female connection member together and thereby form such substantially semi-permanent coupling.
It can be seen that the rear surface portion of the aperture formed in such male connection member which will receive the pin member therein includes a horizontally disposed concave configuration and a vertically disposed convex configuration. This particular aperture configuration is desirable in this articulated coupling arrangement in order for both the male connection member and the female connection member to be able to move in each of the necessary horizontal direction and the vertical direction with respect to one another during operation on a track structure.
Such male connection member, adjacent the outer end surface of the outer end portion thereof, includes a convex configuration which abuttingly engages a complimentary concave surface that is formed on the front face of a follower member. As illustrated in the drawings for this articulated coupling arrangement, the follower member is disposed within the rear portion of the cavity located in the outer end portion of such female connection member. On the rear face portion thereof, this follower member includes a pair of vertically disposed slot-like cavities formed therein.
A first portion of a resilient member is positioned within each of these vertically disposed slot-like cavities. Each such resilient member includes a second portion which extends outwardly from the rear face portion of such follower member. In this manner, a vertically disposed wedge-like element, between the rear wall of the cavity and the follower, can be engaged with the opposed outermost surface area of each such resilient element. This wedge-like element is a necessary component in this articulated coupling arrangement so that during service thereof such follower members and the male connection member can be urged in a forward direction. Consequently, the rear surface portion of the aperture formed in the outer end portion of such male connection member will, at all times, be maintained substantially in mating engagement with such pin member.
Other prior art type articulated coupling arrangements are also taught in U.S. Pat. No. 3,716,148 and Canadian Patent Number 1,231,078.
A problem common to all of the articulated coupling arrangements known to Applicants at the present time, is that they are all susceptible to extraneous foreign matter entering into the articulated connection component, where such foreign matter can be catastrophic. This would be the case, for example, if relative movement between the male connection member and the female connection member is inhibited during negotiations of a curve located in the track structure. Such a circumstance could cause a possible derailment.